Poor Performance from DSS

[To-M]

18 months ago we did not have the Auto Failover; did you send the logs to support so we can see if there are areas that we can investigate?

Others are getting respective performances from posts below to compare - there are more but here is just a small few.

http://forum.open-e.com/showthread.php?t=1392
http://forum.open-e.com/showthread.php?t=1319 (look at the "SQLIO test in iscsi mode" tests)

In the test.log what is the hdparm for sdx?
Any dropped packets for the NICs - look in the same log file for ifconfig -a.

Try changing the following in the iSCS Target settings from Console (CTRL + ALT + W - Tuning options..)

maxRecvDataSegmentLen=262144
MaxBurstLength=16776192
Maxxmitdatasegment=262144
maxoutstandingr2t=8
InitialR2T=No
ImmediateData=Yes

[andrewa]

Todd

Apologies, you are quite right, we only started using fail-over this year as of update 3278.

I have sent out logs to your support guys and hopefully they can spot something I haven't noticed.

hdparm stats look pretty slow, so maybe something wrong with underlying disks/array?


hdparm -t /dev/sda
*-----------------------------------------------------------------------------*


/dev/sda:
Timing buffered disk reads: 58 MB in 3.05 seconds = 19.03 MB/sec

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdb
*-----------------------------------------------------------------------------*


/dev/sdb:
Timing buffered disk reads: 172 MB in 3.15 seconds = 54.64 MB/sec

No dropped packets or collisions on NICs as far as I can see.

Our 2nd box hdparm output looks a bit more healthy

/dev/sda:
Timing buffered disk reads: 4 MB in 4.03 seconds = 1016.08 kB/sec

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdb
*-----------------------------------------------------------------------------*


/dev/sdb:
Timing buffered disk reads: 548 MB in 3.01 seconds = 182.19 MB/sec

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdc
*-----------------------------------------------------------------------------*



Thanks

[To-M]

No problem - hey check the RAID Controller to see if write cache is enabled.

[1parkplace]

I know you are using a different setup, but we use VMWare as well, check out my stats post.

http://forum.open-e.com/showthread.php?t=1449

Drew

[PeterForrest]

thanks for sharing such a nice information.